362 THE MOUNTAIN. 



turtle fauna is the range of the Chrysemys picta, and the 

 characteristic genera are Nanemys, Glyptemys, Calemys, 

 Ptychemys, Cistudo, Chelydra, Ozotheca, Thyrosternura, 

 Malacoclemmys, Emys, and Grapterays, rare, also Aspido- 

 nectes. Several families of testudinata are found on the 

 mountain, some on the mountain proper, others in the 

 streams cutting through the range and flowing from it. 

 These are the Try ony chid ae, Chelydroidae, Cinosternoidae, 

 Emydoideee. 



TRYONYCHIDJE. 



This family is aquatic in its habits, and called soft- 

 shell fresh-water turtles. They inhabit muddy-bottomed 

 streams, and not much is known of their habits. They live 

 upon shell-fish, the larva? of insects, and other substances 

 which they find in the mud. In mill-dams and stagnant pools 

 their sharp-pointed snouts may be seen above the surface of 

 the water, mere dots, the animal being suspended below. 

 These turtles are found rarely on the eastern side of the 

 mountain, but are regular inhabitants of the slow, tortuous, 

 and sluggish streams which descend from the broken plateau 

 of the western side of the range. According to Holbrook, 

 "the flesh of some of these turtles is the most delicate food, 

 surpassing that even of the green turtle." Agassiz enume- 

 rates two genera of Tryonichidse that are found in the 

 waters of Western Pennsylvania. * 



* " The soft-shelled tortoise was not generally known as an in- 

 habitant of New York until after the completion of the Erie Canal, 

 connecting the great lakes with the ocean. Previous to that period, 

 it was supposed to belong exclusively to Southern and Western waters. 

 The description given above was taken, several years since, from a 

 specimen obtained in the Mohawk River. Subsequently, several in- 

 dividuals, as I understand, have been taken from the Hudson River, 

 near Albany." DEKAY, New York Fauna, 



According to Holbrook, " it abounds in the great chain of Northern 

 lakes, both above and below Niagara Falls, and is common in the 

 Mohawk, a tributary of the Hudson River, but is not found in any 

 other Atlantic streams for a distance of nearly eight hundred miles." 



